The present invention relates to geodetic surveying, particularly a system of instrumentation which can assist the surveyor by providing automatic calculation and direct readout of the various parameters and vectors encountered during the course of a survey.
The transit and tape have in great measure been supplanted as basic tools of the surveyor by digital display instruments, such as the angle encoder theodolite described in U.S. Pat. No. 3,768,911 and the electronic distance measuring device described in U.S. Pat. No. 3,778,159. While these newer instruments represent a marked improvement in convenience and accuracy, they nonetheless merely provide the same raw data, i.e. horizontal angle, vertical angle, and range, which the surveyor previously acquired by means of the classic devices. As a result, there remains the matter of translating these data into their more useful component vectors, i.e. horizontal distance, latitude, departure, and elevation.
Some attempts have been made to derive these vectors directly in the measuring instrument, for example by means of an analog approach as described in U.S. Pat. No. 3,677,646; however, few have proven successful. The advent of small electronic calculator elements later made possible the generation of some vector values at the surveyor's station, as described in U.S. Pat. No. 3,895,871, but such practices required the manipulation of data by the operator and were thus basically lacking in automatic function capabilities. Calculators were also employed to derive some vectors from specially prescribed distance measuring procedures, as in U.S. Pat. No. 3,900,260, yet the utility of such schemes was particularly limited.